Re: [PATCH 02/11] drm/sti/sti_hdmi: convert to struct drm_edid

[Jani Nikula <jani.nikula@intel.com>]

On Mon, 24 Jun 2024, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Tue, May 14, 2024 at 03:55:08PM +0300, Jani Nikula wrote:
>> Prefer the struct drm_edid based functions for reading the EDID and
>> updating the connector.
>> 
>> The functional change is that the CEC physical address gets invalidated
>> when the EDID could not be read.
>> 
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> 
>> ---
>> 
>> Cc: Alain Volmat <alain.volmat@foss.st.com>
>> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
>> Cc: Maxime Ripard <mripard@kernel.org>
>> Cc: Thomas Zimmermann <tzimmermann@suse.de>
>> ---
>>  drivers/gpu/drm/sti/sti_hdmi.c | 24 ++++++++++++++----------
>>  1 file changed, 14 insertions(+), 10 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/sti/sti_hdmi.c b/drivers/gpu/drm/sti/sti_hdmi.c
>> index 500936d5743c..3b62ec2d742f 100644
>> --- a/drivers/gpu/drm/sti/sti_hdmi.c
>> +++ b/drivers/gpu/drm/sti/sti_hdmi.c
>> @@ -974,28 +974,32 @@ static const struct drm_bridge_funcs sti_hdmi_bridge_funcs = {
>>  
>>  static int sti_hdmi_connector_get_modes(struct drm_connector *connector)
>>  {
>> +	const struct drm_display_info *info = &connector->display_info;
>>  	struct sti_hdmi_connector *hdmi_connector
>>  		= to_sti_hdmi_connector(connector);
>>  	struct sti_hdmi *hdmi = hdmi_connector->hdmi;
>> -	struct edid *edid;
>> +	const struct drm_edid *drm_edid;
>>  	int count;
>>  
>>  	DRM_DEBUG_DRIVER("\n");
>>  
>> -	edid = drm_get_edid(connector, hdmi->ddc_adapt);
>> -	if (!edid)
>> -		goto fail;
>> +	drm_edid = drm_edid_read_ddc(connector, hdmi->ddc_adapt);
>
> I think you can use drm_edid_read here since the ddc is correctly set up
> with drm_connector_init_with_ddc()
>
>> +
>> +	drm_edid_connector_update(connector, drm_edid);
>>  
>> -	cec_notifier_set_phys_addr_from_edid(hdmi->notifier, edid);
>> +	cec_notifier_set_phys_addr(hdmi->notifier,
>> +				   connector->display_info.source_physical_address);
>> +
>> +	if (!drm_edid)
>> +		goto fail;
>
> Unless I missed something, all the functions can cope with a NULL edid,
> but this jump means in the failure case you'll return stack garbage in
> count. Just drop this check?

Reviving an old thread... the goto fail path returns 0, not count.

BR,
Jani.


>
>>  
>> -	count = drm_add_edid_modes(connector, edid);
>> -	drm_connector_update_edid_property(connector, edid);
>> +	count = drm_edid_connector_add_modes(connector);
>>  
>>  	DRM_DEBUG_KMS("%s : %dx%d cm\n",
>> -		      (connector->display_info.is_hdmi ? "hdmi monitor" : "dvi monitor"),
>> -		      edid->width_cm, edid->height_cm);
>> +		      info->is_hdmi ? "hdmi monitor" : "dvi monitor",
>> +		      info->width_mm / 10, info->height_mm / 10);
>>  
>> -	kfree(edid);
>> +	drm_edid_free(drm_edid);
>>  	return count;
>
> With the two items addressed:
>
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>
>>  
>>  fail:
>> -- 
>> 2.39.2
>> 

-- 
Jani Nikula, Intel